Complex liquid mixtures such as a fragrance or fragrance oils can be delivered to the air by a variety of methods. Exemplary devices which are known to deliver fragrance or fragrance oils include battery or plug-in air freshening devices that contain a fan and/or a heater to accelerate evaporation of the liquid. Such devices, however, have limitations such as inconsistent delivery rates and uneven and inefficient fragrance delivery.
For example, FIG. 1 illustrates an example of a prior art fragrance delivery device. This figure depicts the top view of a fragrance supply bottle and fan combination, within an enclosure, exhibiting less than ideal air flow. As denoted in letter C in FIG. 1, the fan supplies air to the wick without consideration of the air turbulence that exists in such a device, in which the fan and wick are oriented perpendicular to each other. Notice the excess air turbulence (FIG. 1, C) after the air strikes the wick and how the air flow turbulence continues beyond the wick. Also note that much of the air being supplied by the fan misses the wick, which is the area containing the highest fragrance concentration within the unit. Air deflects off the interior side of the enclosure causing further air flow disturbances (FIGS. 1, A and B). This air flow model representative of various prior art devices illustrates an inefficient fragrance delivery pattern because large amounts of fragrance is trapped within the enclosure and does not escape (see FIG. 1, A, B, C). Although weight loss may be significant, fragrance delivery into the surrounding air is marginal at best.
Without the use of air currents required to efficiently evaporate the liquid, devices have relied upon the application of heat. Unfortunately, certain notes of the fragrance compositions may be skewed by the heating element so that the full “bouquet” of the fragrance is not perceived by the subject, and the hedonic impression is diminished. The inefficient fragrance delivery pattern exhibited by prior art devices thus limits the creativity of the perfumer in selecting fragrances for the device. The perfumers may desire use of unique constituents with variable volatility, yet there are instances where a fragrance cannot be developed because the device requires the application of too much heat in order to deliver the vapors of the fragrance.